Soil Drainage Characteristics Research Articles

A growing season water balance model applied to two Douglas fir stands

The forest water balance model presented requires only daily solar radiation, maximum and minimum air temperature, and rainfall as the input weather data. Site parameters are root zone depth, soil water retention and drainage characteristics, estimated canopy leaf area index, and the coefficients of the evapotranspiration and rainfall interception submodels. The evapotranspiration submodel calculates the forest evapotranspiration rate as the lesser of energy‐limited and soil‐limited rates. The former is calculated from the 24‐hour net radiation and the latter from the fraction of extractable water in the root zone. Solar radiation and air temperature are used to calculate net radiation. Interception is calculated from the daily rainfall. The root zone is treated as a single layer with drainage calculated as a function of the root zone water content. Water deficits and the matric potential of the root zone are used to indicate tree Water stress. The model was tested on two Douglas fir stands of different stand density and leaf area index. The coefficients used in the evapotranspiration submodel were found to be the same for both stands. It was also found that over 20% of the growing season rainfall was lost through interception.

EFFECTS OF LAND CAPABILITY ON APPLE PRODUCTION IN SOUTHERN ONTARIO

The effects of land capability on apple production were evaluated for 171 semi-dwarf trees (var. McIntosh on E.M. VII rootstocks) located in 19 orchards in Southern Ontario. Soil, climatic and management variables were analyzed using stepwise regression analysis. Approximately 82% of the yield variation was explained by 12 variables; climatic and management variables accounted for the largest portion of the variation. Most of the soil variables were related to soil drainage characteristics or water retention properties. Land capability class provided a reasonable prediction of potential apple yield. Average apple yield for classes 1 to 4 were 0.85, 0.71, 0.60 and 0.47 kg/cm2, respectively. Subclass limits are proposed for each of the soil characteristics. The most productive lands consisted of soils with loamy sand to sandy loam solums underlain by medium to fine textured II C horizons. There was a poor correlation between apple yield and the lower categorical levels of soil classification, i.e. series and type.

Map Unit Composition Assessment Using Drainage Classes Defined by Landsat Data

AbstractSoil survey map units are designed such that the dominant soil represents the major proportion of the unit. At times, soil mapping delineations do not adequately represent conditions as stated in the map unit descriptions. Digital analysis of Landsat multispectral scanner (MSS) data provides a means of accurately delineating and quantifying soil map unit composition.Digital analysis of Landsat MSS data collected on 9 June 1973 was used to prepare a spectral map for a 430‐ha area in Clinton County, Indiana. Sixteen spectral classes were defined, representing 12 soil and 4 vegetation classes. The 12 spectral soil classes correlated with soil drainage characteristics and were grouped into four drainage classes. The four spectral vegetation classes were grouped for convenience into one vegetation class.The soil delineations produced using these groupings were compared to a conventionally prepared soil map. Three map units were investigated in detail: (i) Mahalasville silty clay loam, poorly drained; (ii) Reesville silt loam, 0 to 2% slopes, somewhat poorly drained; and (iii) Xenia silt loam, 2 to 6% slopes, eroded, moderately well drained.Results indicate that soil drainage characteristics can be identified. Correlation of drainage characteristics with soil series allows for the composition of soil map units to be accurately ascertained.

Frost Heaving in Alfalfa Establishment on Soils with different Drainage Characteristics1

AbstractThe susceptibility of alfalfa (Medicago sativa L.) to frost heaving is a major problem in stand establishment in southern Illinois. This study was conducted at Carbondale, Illinois, to determine the effects of frost heaving on the establishment and production of alfalfa cultivars in relation to soil drainage characteristics. Four alfalfa cultivars (‘Cody’, ‘Spredor’, ‘Weevlchek’, and ‘WL‐307’) were seeded on three soil series, a deep well‐drained AIford (Typic Hapluadalf, fine‐silty mixed mesic), a moderately well‐drained Hosmer (Typic Fragiudalf, fine‐silty, mixed, mesic) with a fragipan starting at a depth of 60 to 70 cm, and a nearly level poorly‐drained Weir (Typic Ochraqualf, fine, montmorillonitic, mesic). Piezometers were installed in each soil to monitor the presence of perched water tables and their position to the soil surface. Small wooden dowels were used to assess soil movement in relation to alfalfa seedling heave. The higher amount of heaving as measured by the distance wooden dowels were raised above a reference point occurred when the night temperature was a few degrees below freezing and the day temperature was above freezing, with a perched water table near the soil surface. Poorly‐drained, Weir soil had the highest perched water table, most alfalfa seedling heave, greatest alfalfa seedling winterkill, and most dowel heave. In contrast, well‐drained Alford series had no perched water table, no appreciable seedling heave or winterkill, and least dowel heave. No significant differences in amount of frost heaving of seedlings were noted amonga alfalfa cultivars on any drainage site. Highest dry matter yields were obtained on the well‐drained Alford site; significant yield reductions occurred as soil drainage class became more poorly drained. Alfalfa stands were successfully established on the well‐drained Alford series and the moderately well‐drained Hosmer series. Soil drainage characteristics did influence alfalfa establishment and production in the climatic transitional zone of the central U. S. Poorly‐drained soils should not be considered for alfalfa production.

Long Term Interactions of Microorganisms and Prudhoe Bay Crude Oil in Tundra Soils at Barrow, Alaska

Oil was recovered from tundra soils two and seven years after spillage. Oil persisted in the upper soil layer. The depth of penetration appears to depend on soil moisture and drainage characteristics. Maximal penetration seems to occur within one year of spillage. Biodegradation of the oil was indicated by changes in the ratio of gas chromatographically resolved to unresolved components. Individual components appear to be preferentially degraded, but no evidence was found for significant preferential degradation of structural classes of hydrocarbons. Numbers of microorganisms were different in oil contaminated and reference soils generally showing continued enrichment, but in some soils showing inhibition of microbial populations.

Evaluation of Remote Sensors For Exploration Geomorphology: ABSTRACT

Remote-sensor imagery embraces black and white aerial photography--including black and white infrared photography and various film-filter combinations--color aerial photography, color infrared aerial photography, thermal infrared, and radar. For the 3 general types of geomorphic exploration techniques--drainage analysis, tonal analysis, and fracture analysis--no single remote sensor is best. Terrain, vegetative cover, and extent of human activity influence the selection of imagery for analysis. Black and white and color photography seem best for routine surface--drainage analysis, especially of low-order streams. Thermal infrared and color infrared give considerable information on groundwater-discharge locations and soil-drainage characteristics. Radar imagery allows excellent mapping of higher order drainage patterns of large areas, and is least affected by vegetative cover. Tonal anomalies are best seen on black and white infrared and black and white panchromatic photography. Color photography is less useful for this technique, and color infrared is poor to unusable, especially in grass-covered regions. Thermal infrared is very poor, and radar cannot be used for tonal studies in exploration geomorphology. Fracture-trace analysis is done best on stereo-aerial photography of all types, and least well on thermal-infrared and radar imagery. Lineament analysis is done best on aerial photographic mosaics, and particularly well on radar. Radar and aerial photographic mosaics are well-suited for regional studies, as are images from satellites; aerial photographs and thermal infrared imagery are best for local, detailed studies. End_of_Article - Last_Page 790------------